It's "I am a girl who likes..." Saying it with "like" sounds strange and aside from that, "I am a girl who likes" sounds like you are about to tell us what are the different things you like. Even if its not more than one thing that you like, saying "likes" is better than "like".

"Likes". You could make it into two separate sentences: "I am a girl", "she likes ... something".

It is "I'm a girl who like." Bcause "likes" means somebody, just one person. However, "like" means a lot of peple like you.

Answer is 'likes' cause girl is third person. but if it is in plural form, you can not use 's' or 'es' with verb.